1. Field of the Invention
The present invention relates to a document reading apparatus capable of displaying, as an image, a foreign matter position.
2. Description of the Related Art
Conventionally, an image reading apparatus (document reading apparatus) has been known that has a flow-reading mode in which an image of an original passing through an original reading position is read by an optical scanning unit that remains stopped at the original reading position, while originals are conveyed one by one along a reading glass by an automatic original feeder. However, if foreign matter such as dust or stain is present at the original reading position on the reading glass, a streak is produced in the read image.
To prevent a streak from being produced in a read image, an image reading apparatus has been proposed that has a foreign matter detection unit for detecting a position of foreign matter on a reading glass (see, for example, U.S. Pat. No. 7,719,726). This image reading apparatus displays a message for prompting cleaning the reading glass when foreign matter is detected, and selectively illuminates a foreign matter detection area of the reading glass when the reading glass is cleaned.
With the above proposed image reading apparatus which certainly has an illumination unit having a plurality of light emitting devices, however, it is difficult to indicate the foreign matter detection area in detail. Accordingly, there is a fear that a user cannot accurately recognize a position of foreign matter based on the illuminated foreign matter detection area.